Is this issue strictly related to the turbo engines, or could this also be applicable to the naturally aspirated engine as well. Mine (528i) also seems to lag a bit on initial acceleration. It seems a tad lazy starting from a stop. In sport mode, however, there is no lag or laziness whatsoever. Just wondering if it's something that needs to be adressed on my particular model.

Edmunds Inside Line has noted the same issue with their long term 528 as well. Its not the turbo, its the throttle and transmission programming. Its not related to actual engine power at all. .